The present invention relates to a system comprising a vacuum pumping mechanism and a motor for driving the mechanism.
Hereto, vacuum pumping systems are known which comprise a vacuum pumping mechanism and a motor for driving the mechanism. The pumping system may be connected for exhausting fluid from a processing system for processing wafers, such as semi-conductor wafers, comprising a processing chamber and a transfer chamber. A condition of such a vacuum pumping system deteriorates during operation of the system and a maintenance activity is required to restore, repair or maintain the condition of the system. For instance, a filter may become clogged with particles and require replacement. Previously, such a maintenance activity is scheduled dependent on elapsed time since delivery of the system to a customer or since the performance of a previous maintenance activity. For instance, a maintenance activity may be scheduled for a month after delivery and regularly thereafter. Such a schedule takes no account of the actual requirement for a maintenance activity since a condition of the system may not require maintenance when a maintenance activity is scheduled if for example the system has been operative for less time than was envisaged. Alternatively, and perhaps more dangerously, a condition may require maintenance in advance of a scheduled maintenance activity because the system has been used more extensively than envisaged. It is therefore desirable to perform a maintenance activity on the system according to an actual, real time, requirement of a condition of the system.
It is also known to provide a vacuum pumping sub-system together with other sub-systems in a processing system. An abatement system is one example of such a sub-system. The abatement system treats gas exhausted from vacuum pumping systems to remove hazardous process by-products or other substances from the exhausted gas. In order to remove such substances an abatement system consumes resources such as power, water, gas or other chemicals. If the pumping arrangement is connected for pumping gas from a processing chamber, for instance a processing chamber for processing semi-conductor wafers, the abatement system is activated prior to commencement of a processing procedure and continues to operate at a fixed capacity which is sufficient to treat a maximum expected flow rate of gas from the pumping arrangement. If the abatement system were operated at less than such a fixed capacity some gas may be released into the environment without treatment. It will be appreciated that if the abatement system is set to run at a fixed capacity then there will be redundancy in the system when gas is exhausted from the vacuum pumping system at less than a maximum expected rate or when no gas is exhausted. It is desirable to control the abatement system so that it is operating at a sufficient capacity to treat exhausted gas but without consuming resources unnecessarily.